ERBB2 and breast cancer: Clinical trial results from a phase III randomized trial showed a valid increasing in PFS (median PFS of 5.7 months versus 4.4 months) and a 24% reduction in relative risk (RR) in the margetuximab plus chemotherapy arm compared to the trastuzumab plus chemotherapy arm in advanced HER2-positive breast cancer patients (after receiving targeted therapy previously), with a median overall survival (OS) of 21.6 months, compared with a median OS of 19.8 months in the trastuzumab group, and the regimen also had an acceptable safety profile (59).